Well safety valve having mechanism shielded from fluid flow

ABSTRACT

A well safety valve to be lowered into and located within a well and be actuated from the surface of the earth by exertion of upward tensioning force on a cable or the like, with the valve having mechanism for effecting downward displacement of the valve element or elements proper in response to upward movement of the cable by virtue of a reversing mechanism which is located out of the path of and therefore protected from the flow of well fluid, and which is preferably located in the valve body beneath a movable valve element and associated pilot valve element and beneath the location at which well fluid enters the body past the main valve.

United States Patent 1191 Boyadjieff et a1.

1451 Nov. 12, 1974 A- E Eu a-521m 8/1944 Erwin 166/72 Clark et a1. 166/72 Primary E.raminer.lames A. Leppink Attorney, Agent, or Firm-William P. Green 57 I ABSTRACT A well safety valve to be lowered into and located within a well and be actuated from the surface of the earth by exertion of upward tensioning force on a cable or the like, with the valve having mechanism for effecting downward displacement of the valve element or elements proper in response to upward movement of the cable by virtue of a reversing mechanism which is located out of the path of and therefore protected from the flow of well fluid, and which is preferably located in the valve body beneath a movable valve element and associated pilot valve element and beneath the location at which well fluid enters the body past the'main valve.

14 Claims, 4 Drawing Figures III/III],

ATENTEU NOV 12 1974 CROSS REFERENCE TO RELATED APPLICATION The valves of the present invention represent improvements on the valves disclosed and claimed in our copending application Ser. No. 252,808 filed May 12, 1972 on Remotely Operated Well Safety Valves, which was a continuation in part of our co-pending application Ser. No. 203,142 filed Nov. 30, 1971 on Remotely Operated Safety Valves and now abandoned.

BACKGROUND OF THE INVENTION This invention relates to improved well safety valves for closing off the flow of fluid upwardly within the well when any of various adverse conditions develops.

The safety valve assemblies of the present invention are of the general type disclosed and claimed in my above identified co-pending application, in which a valve located deep within a well is actuated from the surface of the earth by an elongated preferably flexible member, desirably a flexible cable, extending upwardly within the well. The cable may be maintained under longitudinal tension when the valve is in open condition, so that any release of that tensioned condition will automatically release the valve for return to a normally closed position in which the fluid flow is positively shut off. Thus, if for any reason the cable is broken, as by an earthquake or the like, or if an actuating device which maintains the cable under tension is accidentally or intentionally de-energized, the valve will close and protect the environment from escape of well fluid thereinto. The actuating unit may take the form of a piston and cylinder mechanism located in the well near the surface of the earth, and which maintains the cable under tension only so long as pressurized fluid is supplied to the cylinder. If it is desired to purposefully close off the well, the pressure of the actuating fluid may be purposely released; or if any of the lines or equipment conducting the actuating fluid breaks or develops a leak, the tension on the cable will be released automatically without the necessity for human intervention.

SUMMARY OF THE INVENTION The present invention is directed to improvements in the valve mechanism of a safety assembly of the above discussed type. For one thing, the improved apparatus,

of the invention is especially designed to so construct and locate the valve and its actuating mechanism that a maximum number of the moving parts are positioned out of the path of the well fluid through the tool, so that the continual flow of well fluid through the tool and well when the valve is open and the well is in production cannot damage and gradually render inoperative the valve mechanism. In particular, a reversing mechanism which is provided for producing downward opening movement of the valve in response to upward movement of the actuating cable is located out of the path of the well fluid, and thereby shielded from abrasion or damage which might otherwise result if the reversing mechanism were in the path of fluid flow. Structurally, the valve actuating mechanism may include a rod or other actuating part which is movable LII upwardly relative to the-safety valve proper by upward movement of the actuating cable, with this rod or the like having a portion actually received within and movable upwardly relative to the valve and/oran associated pilot valve element, and with the reversing mechanism preferably being located beneath the uppermost portion of the valve proper, and for bestresults being located at the lower end of the pilot valve element. The actuating rod' or other member may extend downwardly through the main safety valve, and then into a passage within the pilot valve element, and the reversing mechanism may consist of a flexible member connected at one end to the actuator within the pilot valve element and extending downwardly therefrom about a direction reversing wheel carried by the body of the tool, and then upwardly for connection to the pilot valve element itself.

The well fluid preferably enters the body of the valve device through an opening or openings which direct the fluid into the body above the main valve element in its open condition. The pilot valve element and reversing mechanism may then be located beneath that main valve element, and be shielded thereby from contact with the well fluid.

BRIEF DESCRIPTION OF THE DRAWING two partial views which are vertical continuations of one another to allow the parts to be shown at a large enough scale for clarity;

FIG. 3 is a further enlarged view showing the lower portion of the tool with the valve in its closed condition; and

FIG. 4 is a fragmentary representation of the pilot valve element in its open condition.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, there is represented in that Figure at 10 a well containing the usual casing 11, with an essentially conventional string of production tubing 12 extending downwardly within the well and spaced from casing 11 from the location of a diagramatically represented well head 13 at the surface of the earth. The lower extremity of the tubing string 12 terminates at a production zone 14, from which production fluid is to flow upwardly through string 12 to a storage tank 116 or appropriate distribution line. The tubing string is formed in conventional manner of a series of tubing sections connected in an end to end series by internally threaded couplings represented at 15. In lieu of the typically illustrated type of well drilled directly into the surface of the earth, it is contemplated that the present well safety apparatus may also be utilized in the drilling of underwater wells, as from a barge or ship floating on the surface of a body of water, with the well casing and its contents extending downwardly through the water to the'ocean floor or the like, and then intothe earth at that location.

The safety valve unit proper is designated generally by the number 17 in FIG. 1, and is set in fixed position within the lower portion of tubing string 12 by a landing and sealing unit represented at 18. Unit 18 may be constructed integrally with valve unit 17, or may be a separately formed attached conventional landing and sealing unit as illustrated, rigidly connected to the upper end of the valve unit 17 by a threaded connection 19 (FIG. 2). The safety valve is actuated and controlled by an elongated flexible line 20, preferably of the type commonly referred to as a wireline. This line or cable extends upwardly to the surface of the earth for control by a powered operating mechanism designated generally at 21. The line 20 may be any conventional or known type of flexible cable or the like, including elements of this type formed of either a single wire or strand, or a number of wires or strands interwoven or wound together.

The landing and sealing unit 18 is typically and somewhat diagramatically illustrated as of the same conventional key-type shown and described in our above identified co-pending applications. Specifically, this unit 18 may include a tubular body member 22 connected at its lower end to the upper end of body 23 of valve unit 17 by the previously mentioned threaded connection 13, with an annular seal ring 24 of rubber or other elastomeric material clamped between shoulders on elements 22 and 23 as seen in FIG. 2 for annular engagement with the inner surface of tubing 12 to form a fluid tight seal therewith preventing upward flow of fluid about the outside of elements 22 and 23 at the location of seal 24. Disposed about body 22, the landing and sealing unit 18 includes a sleeve or mandrel 25 containing apertures through which a number of circularly spaced locking keys or dogs 26 project radially outwardly for interfitting reception within a mating locating groove or plurality of grooves 27 formed in a coacting locating or landing nipple'28 connected into tubing 12. As is conventional in this type of device, keys 26 may be spring pressed radially outwardly relative to sleeve 25 for automatic reception within the groove or grooves 27 when they reach the location of the groove, with the keys then being locked in their outer holding positions in conventional manner by predetermined manipulation of body 22 from the surface of the earth. For example, the keys may be locked in their outer positions by a rapid vertical jarring movement of body 22 serving to shear a connection between the body and sleeve 25 and thereby move a locking or camming portion of the body into a position behind or radially inwardly of the keys. After being set by this type motion, the keys thereafter very positively lock sleeve 25 and body 22 against both upward and downward movement relative to section 28 of the tubing, to thereby positively retain the valve unit 17 in its FIG. 1 position in the lower portion of the tubing string. Any other type of conventional landing equipment may of course be substituted for the particular key-type device typically flexible line 20 is connectible, and through which a central vertical passage 29 is formed for passing production fluid upwardly through the interior of this actuating unit. The cylinder 30 of the piston and cylinder mechanism 21 is an essentially tubular element having a vertical cylindrical internal surface 31, and contains a piston 32 which is movable upwardly and downwardly along the vertical axis 33 of the well. The piston 32 has an upper enlarged diameter portion 34 slidably received within and sealed by an O-ring 35 with respect to the inner cylindrical surface 31 of cylinder 30. An annular hydraulic cylinder chamber 36 is thus formed between the cylinder and piston, acting to force the piston upwardly relative to the cylinder in response to the injection of pressure fluid into the chamber 36. The lower end of chamber 36 is closed by provision of a reduced diameter portion 37 of the cylinder, having an internal surface 38 slidably engaging and receiving the lower reduced diameter portion 39 of the piston, and sealed with respect thereto by an annular O-ring 40. Pressure fluid is introduced into the lower end of cylinder chamber 36 through a small fluid inlet line 41, connecting into the cylinder chamber at 42.

The upper end of piston 32 carries a spider 43, which supports a tubular element 44 at a central location within the piston, so that the flexible line 20 may extend upwardly through this tubular portion 44 and be attached to an upper enlarged head element 45 shaped to serve as a fishing neck, for engagement with a fishing tool to pull the flexible line upwardly if and when desired. Upward movement of the piston acts to displace head element 44 and the connected flexible line upwardly, to open the valve unit 17 and maintain the flexible line under tension.

The piston and cylinder mechanism 21 is preferably suspended in the well from the well head 13, from which the usual main flow control valve assembly or Christmas Tree projects upwardly, the lower portion of this valve assembly being represented at 46 in FIG. 2. To suspend the actuating piston and cylinder mechanism from the well head, there is desirably provided between elements 13 and 46 an adapter flange or ring 47, suitably secured to the flanges of elements 13 and 46, and appropriately sealed with respect thereto as by rings represented at 48 and 49. The upper end of cylinder 30 may be connected threadedly at 50 to a short suspending tube 51, sealed with respect to the cylinder at 52 and 53, and annularly sealed with respect to flange 47 at two vertically spaced locations 54 and 55. One or more locking dogs 56 may be threadedly connected into element 47 for projection into an annular external groove 57 formed in part 51, to suspend that part and the connected piston and cylinder mechanism in the illustrated position within the well. Actuating pressure fluid may be supplied to the piston and cylinder mechanism through an inlet passage 58 communicating through small passages 59 and 60 in elements 51 and 30 respectively with the previously mentioned line 41 extending downwardly to the lower end of cylinder chamber 36. A fishing neck 61 may be connected onto the upper end of part 51, for engagement with an appropriate fishing tool to enable removal of the unit 21 upwardly from the well when desired. The actuating pressure fluid is supplied to passage 58 from any approwhich may include two vertically successive rigid tubular body sections 62 and 63 threadedly connected together at 64, and annularly sealed with respect to one another at 65. The lower end of section 63 of the valve body may be closed by a bottom downwardly tapering nosepiece 66, threadedly connected to and sealed with respect to section 63 at 67. The lower end of upper section 62 of the valve body retains an annular valve seat element 68 in fixed position within the body 'by clamping that element between the lower extremity of section 62 and a shoulder 69 formed in section 63. An O-ring or other seal element 70 forms a seal about the periphery of seat element 68,'which has a downwardly facing annular seat surface 71 engageable by an annular sealing part 72 of a vertically movable poppet type valve element 73 mounted in section 63 of the body. In the FIG. 2 open position of the main valve element 73, production fluid enters the interior of section 63 through one or more apertures 74 formed in the side wall of tubular body section 63. This production fluid flows radially inwardly across the upper side of valveelement 73, and then upwardly through tubularj valve'seat element 68 and the interior of elements 62 and 22 for delivery to the surface of the earth through tubing 12. In the FIG. 3 closed position of valve element 73, the flexible seal element 72 of the valve element engages'seat part 68 annularly in sealing engagement, to close off any further upward flow of the production fluid into the tubing.

The valve element 73 has an upper horizontal top wall 75, and a depending annular skirt portion 76, both having a common external cylindrical surface 77 centered about the vertical axis 33 of the well and slidably engaging the internal vertical cylindrical surface 78 formed in body section 63. An annular O-ring 79 forms a seal between the valve element 73 and body section 63, to prevent fluid flow vertically past the location of and contains a passage 83 through which rod 81 projects downwardly, with an O-ring 84 and a series of O-rings 184 providing a fluid tight seal between parts 81 and 82 as shown in FIG. 3. The upper end of element 82 is convexly rounded at 85, for engagement with a flexible annular seal ring 86 contained within a recess in the underside of top wall 75 of valve element 73, to block off fluid flow through bleed passage 80 and past rod 81 when the pilot valve is in its FIGS. 2 and 3 position of engagement with element 86. When, however, the pilot valve element 82 is displaced down-' wardly a short distance relative to seal element 86, fluid can flow between the underside and the upper side of top wall of main valve element 73, as seen in FIG. 4, to bleed pressure fluid from the underside of main piston 73 to its upper side and thereby equalize the pressure at these opposite sides in a manner enabling downward movement of element 73 by the pressure fluid. The pressure of the well fluid about and beneath unit 17 is at all times applied to the underside of valve 82 through a number of apertures 166 formed in part 66, and is applied to the underside of main valve 76 through a slot 182 in skirt 282 of valve 82, and through a gap 197 extending about a flange 97 on valve 84.

Beneath the mentioned passage 83 within which rod 81 is a close sliding fit, pilot valve element 82 contains an enlarged diameter cylindrical passage 87, closely receiving and slidably engaging an enlarged diameter externally cylindrical portion 88 of the rod. At its lower end, this portion 88 is connected at 89 to a flexible cable or line 90, which extends downwardly to the location of a pulley or sheave 91 mounted rotatably to body section 66 for rotation about a transverse horizontal axis 92. Cable extends about the underside of the sheave or wheel 91, through 180 degrees, and then extends upwardly at 93 for connection at 94 to the lower end of pilot valve element 82. Thus, the exertion of upward force on rod 81 acts through the reversing cable 90 and wheel 91 to pull pilot valve element 82 downwardly relative to the body of the valve and main valve element 73. Such downward movement of the pilot valve element is resisted by a coil spring 95 which is confined between a shoulder 96 formed on valve body part 63 and the annular flange 97 formed on the periphery of the pilot valve element 82. Externally, the upper portion of the pilot valve element has a cylindrical portion 98 which is a sliding fit within internal cylindrical surface 99 in the skirt 76 of the main valve element 73, and is sealed with respect thereto by an annular O-ring 100.

The upper end of the valve actuating rod 81 is preferably connected to flexible line 80 detachably, in a manner enabling the valve unit 17 to be lowered and set in the well before attachment of the line 20 thereto. For this purpose, the detachable connection may include a hollow upwardly opening essentially tubular chuck element 101, having a side wall containing an internal annular groove 102 within which the lower enlarged portions 103 of the series of resilient fingers 104 on a quick disconnect part 105 are receivable inthe FIG. 2 connecting position. A camming or locking element 106 may be connected to the lower end of a typically rigid vertical rod depending from a landing weight 107 which is in turn connected to the lower end of the flexible line 20. The landing weight 107 may be located closely adjacent to the upper end of the landing unit 18. After fingers 103 have been moved downwardly into groove 102, element 106 can be pulled upwardly into the interior of finger 103, to hold them radially outwardly in the groove and against radially inward retraction from the FIG. 2 connecting position and thereby form the desired connection between line 20 and rod 81. The connection may be broken if desired at any time by exertion of a relatively heavy upward jarring force on line 20, to break an appropriate shear pin 107 permitting upward movement of line 20 and element 106 relative to fingers 103, so that element 106 may free the fingers for inward retraction from groove 102. This type of quickly releas'eable connection is of course well known in the art, and will not therefore be discussed in any greater detail herein.

To now describe a cycle of use of the illustrated equipment, the first step in installing the equipment within a well is to lower valve unit 17 and the connected landing and sealing unit 18 into tubing 12 by an appropriate landing and running too] of any conventional construction. At the time of lowering of units 17 and 18, theyare of course disconnected from line 20, and the actuating unit 21 at the surface of the earth is not yet positioned in the well. After the lowering tool has actuated keys 26 to lock units 17 and 18 in the lower portion of the tubing, at the production zone, the lowering tool is removed from the well, and cable 20 with its landing weight 107 and quick disconnect elements 103, 106, etc. is lowered into the well, and tingers 103 are appropriately locked within groove 102 of wardly in a manner placing line 20 under tension, and I actuating valve 73 from its FIG. 3 closed position to its FIG. 3 open position. More specifically, the upward force exerted on line 20 displaces rod 81 upwardly relative to valve elements 73 and 82, to pull upwardly on cable 90 at 89, and through the reversing wheel 91 pull downwardly on pilot valve 82. The initial downward movement of the pilot valve relative to main valve element 73, to the FIG. 4 slightly open position of the pilot valve, relieves the pressure at the underside of valve 73 by bleeding fluid upwardly through passage 80 to the upper side of the valve, so that the pressure at the two sides of the valve is equalized, enabling the valve 73 to follow the downward movement of pilot valve element 82 by gravity. As the pilot valve continues to move downwardly, main valve 73 follows it to the fully open position of FIG. 2, in which the upper surface of the main valve element is located at the bottom of the fluid inlet aperture 74 in the side wall of the valve body. The well fluid may then enter aperture 74, flow radially inwardly therefrom and up through valve seat 68 into and through the interior of the upper portion of the valve body and tube 22, to ultimately discharge from the upper end of tube 22 for flow upwardly through tubing 12 to the surface of the earth, with ultimate discharge from the valve head to storage tank 116. The line 20 is maintained under tension, and valve element 73 is maintained in its FIG. 2 open position, continuously during the production of well fluid through the valve mechanism to the surface of the earth. If for any reason the line 20 should break, as for instance under earthquake conditions or other adverse circumstances, the

tension on rod 81 and the connected parts is immediately released, permitting downward movement of rod 81 to its FIG. 3 position, and by virtue of the reversing connection of cable 90 permitting upward movement of pilot valve 82 and main valve 73 under the influence ofspring 95 to their upper FIG. 3 closed position. Thus, the upward flow of fluid through the safety valve is completely shut off, to protect the upper portion of the production tubing and casing from the production fluid, and thereby prevent possible leakage into the surrounding earth and/or water. Similarly, if the pressure of fluid 36 in actuating unit 21 is relieved by actuation of valve 63, or by rupture of any line leading to or communicating therewith, piston 32 is immediately permitted to return downwardly, and relieve the pressure on line 20 in a manner permitting closure of valves 82 and 73. The valve elements 73 and 82 are very positively held in their closed conditions by the pressure of the well fluid communicated to the underside of elements 73 and 82 through passages 166.

While certain specific embodiments of the present invention have been disclosed as typical, the invention is of course not limited to these particular forms, but rather is applicable broadly to all such variations as fall within the scope of the appended claims.

We claim:

1. In well safety apparatus, including a safety valve body to be lowered into a well-and located therein, a main valve element movable vertically within said body between open and closed positions, a pilot valve element movable relative to said main valve element between an open position permitting fluid flow through a bleed passage from one side of the main valve element to the other and a closed position closing off such flow, and a member extending upwardly to the surface of the earth for actuating said valve elements; the improvement comprising an operator connectible to said member for actuation thereby and having a portion received within the interior of at least one of said valve elements and movable upwardly relative thereto by upward displacement of said actuating member, and reversing means actuable in response to said upward movement of said portion of said operator which is within said one element to displace said pilot valve element downwardly.

2. The improvement in well safety apparatus as recited in claim 1, in which said operator extends downwardly, within said bleed passage in said main valve element, and acts by upward movement within said bleed passage to cause downward movement of said pilot valve element through said reversing means.

3. The improvement in well safety apparatus as recited in claim 1, in which said portion of the operator is received within and movable relative to said pilot valve element.

4. The improvement in well safety apparatus as recited in claim 1, in which said operator is received within and movable relative in both the main valve element and said pilot valve element.

5. The improvement in well safety apparatus as recited in claim 1, in which said reversing means are located beneath the uppermost portion of said main valve element.

6. The improvement in well safety apparatus as recited in claim 1, in which said reversing means are located at the lower end of said pilot valve element.

7. The improvement in well safety apparatus as recited in claim 1, in which said reversing means include a rotatable element and a flexible connector element extending downwardly from said operator about said rotatable element and then upwardly for attachment to said pilot valve element.

8. The improvement in well safety apparatus as recited in claim 1, in which said bleed passage extends vertically through a wall of said valve element, said pilot valve element being located at the underside of said wall and operable by upward movement relative to the wall to close off fluid flow through said bleed passage, said pilot valve element having a vertical passage extending downwardly beneath said bleed passage in the main valve element, and said operator extending downwardly through said bleed passage and into said passage in the pilot valve element and being movable vertically within both of said passages.

9. The improvement in well safety apparatus as recited in claim 1, in which said bleed passage extends vertically through a wall of said main valve element,

, 10 valve body to be lowered into and located within a well, valve means in said body movable relative thereto between an open position in which well fluid flows from the exterior of said body to its interior and then upsaid pilot valve element being located at the underside of said wall and operable by upward movement relative to the wall to close off fluid flow through said bleed passage, said pilot valve element having a vertical passage extending downwardly beneath said bleed passage in the main valve element, and said operator extending downwardly through said bleed passage and into said passage in the pilot valve element and being movable vertically within both of said passages, said reversing means being connected to said operator near the lower end of said pilot valve element.

10. The improvement in well safety apparatus as recited in claim 1, in which said bleed passage extends vertically through a wall of said main valve element, said pilot valve element being located at the underside of said wall and operable by upward movement relative to the wall to close off fluid through said bleed passage, said pilot valve element having a vertical passage extending downwardly beneath said bleed passage in the main valve element, and said operator extending downwardly through said bleed passage and into said passage in the pilot valve element and being movable vertically within both of said passages, said reversing means including a rotatable element mounted to said body downwardly beneath said pilot valve elementand said main valve element, and a flexible element connected to a lower portion of said operator and extending downwardly therefrom and about said rotatable element and then upwardly to a location of connection to a lower portion of said pilot valve element.

11. The improvement in well safety apparatus as recited in claim 10, including a spring disposed about said pilot valve element and about said passage therein and said operator and yieldingly urging the pilot valve element upwardly relative to said body.

12. In well safety apparatus including a hollow safety wardly through the well and a closed position preventing such flow, and an elongated member extending upwardly toward the surface of the earth and operable upon upward displacement to open said valve means, said body having a side wall containing at least one aperture through which well fluid flows into the interior of the body at the upper side of said valve means and then upwardly through said body in the open condition of the valve means; the improvement comprising reversing means located beneath the uppermost portion of said valve means out of the path of said well fluid which enters said body through said aperture at the upper side of said valve means and operable to actuate said valve means downwardly toward open position in response to upward movement of said actuating member.

13. The improvement in well safety apparatus as recited in claim 12, including means forming a valve seat in said body above said aperture, said valve means including a valve element movable upwardly past said aperture and into engagement with said valve seat in said closed position of said valve means.

14. The improvement in well safety apparatus as recited in claim 13, in which said valve element contains a vertical bleed passage with a second valve seat at its lower end, said valve means including a pilot valve element at the underside of said first mentioned valve element and movable relative thereto into and out of contact with said second seat, there being an operator extending downwardly from said actuating member through said bleed passage and into an aligned vertical passage in said pilot valve element, said reversing means including an element mounted rotatably to said body beneath said pilot valve element, and a flexible element connected at opposite ends to lower portions of said operator and said pilot valve element and extending about said rotatable element to reverse direction of the flexible element, there being a spring within said body disposed about said pilot valve element and said operator and urging said pilot valve element upwardly. 

1. In well safety apparatus, including a safety valve body to be lowered into a well and located therein, a main valve element movable vertically within said body between open and closed positions, a pilot valve element movable relative to said main valve element between an open position permitting fluid flow through a bleed passage from one side of the main valve element to the other and a closed position closing off such flow, and a member extending upwardly to the surface of the earth for actuating said valve elements; the improvement comprising an operator connectible to said member for actuation thereby and having a portion received within the interior of at least one of said valve elements and movable upwardly relative thereto by upward displacement of said actuating member, and reversing means actuable in response to said upward movement of said portion of said operator which is within said one element to displace said pilot valve element downwardly.
 2. The improvement in well safety apparatus as recited in claim 1, in which said operator extends downwardly, within said bleed passage in said main valve element, and acts by upward movement within said bleed passage to cause downward movement of said pilot valve element through said reversing means.
 3. The improvement in well safety apparatus as recited in claim 1, in which said portion of the operator is received within and movable relative to said pilot valve element.
 4. The improvement in well safety apparatus as recited in claim 1, in which said operator is received within and movable relative in both the main valve element and said pilot valve element.
 5. The improvement in well safety apparatus as recited in claim 1, in which said reversing mEans are located beneath the uppermost portion of said main valve element.
 6. The improvement in well safety apparatus as recited in claim 1, in which said reversing means are located at the lower end of said pilot valve element.
 7. The improvement in well safety apparatus as recited in claim 1, in which said reversing means include a rotatable element and a flexible connector element extending downwardly from said operator about said rotatable element and then upwardly for attachment to said pilot valve element.
 8. The improvement in well safety apparatus as recited in claim 1, in which said bleed passage extends vertically through a wall of said valve element, said pilot valve element being located at the underside of said wall and operable by upward movement relative to the wall to close off fluid flow through said bleed passage, said pilot valve element having a vertical passage extending downwardly beneath said bleed passage in the main valve element, and said operator extending downwardly through said bleed passage and into said passage in the pilot valve element and being movable vertically within both of said passages.
 9. The improvement in well safety apparatus as recited in claim 1, in which said bleed passage extends vertically through a wall of said main valve element, said pilot valve element being located at the underside of said wall and operable by upward movement relative to the wall to close off fluid flow through said bleed passage, said pilot valve element having a vertical passage extending downwardly beneath said bleed passage in the main valve element, and said operator extending downwardly through said bleed passage and into said passage in the pilot valve element and being movable vertically within both of said passages, said reversing means being connected to said operator near the lower end of said pilot valve element.
 10. The improvement in well safety apparatus as recited in claim 1, in which said bleed passage extends vertically through a wall of said main valve element, said pilot valve element being located at the underside of said wall and operable by upward movement relative to the wall to close off fluid through said bleed passage, said pilot valve element having a vertical passage extending downwardly beneath said bleed passage in the main valve element, and said operator extending downwardly through said bleed passage and into said passage in the pilot valve element and being movable vertically within both of said passages, said reversing means including a rotatable element mounted to said body downwardly beneath said pilot valve element and said main valve element, and a flexible element connected to a lower portion of said operator and extending downwardly therefrom and about said rotatable element and then upwardly to a location of connection to a lower portion of said pilot valve element.
 11. The improvement in well safety apparatus as recited in claim 10, including a spring disposed about said pilot valve element and about said passage therein and said operator and yieldingly urging the pilot valve element upwardly relative to said body.
 12. In well safety apparatus including a hollow safety valve body to be lowered into and located within a well, valve means in said body movable relative thereto between an open position in which well fluid flows from the exterior of said body to its interior and then upwardly through the well and a closed position preventing such flow, and an elongated member extending upwardly toward the surface of the earth and operable upon upward displacement to open said valve means, said body having a side wall containing at least one aperture through which well fluid flows into the interior of the body at the upper side of said valve means and then upwardly through said body in the open condition of the valve means; the improvement comprising reversing means located beneath the uppermost portion of said valve means out of the path of said well fluid which enters said body through said aperture aT the upper side of said valve means and operable to actuate said valve means downwardly toward open position in response to upward movement of said actuating member.
 13. The improvement in well safety apparatus as recited in claim 12, including means forming a valve seat in said body above said aperture, said valve means including a valve element movable upwardly past said aperture and into engagement with said valve seat in said closed position of said valve means.
 14. The improvement in well safety apparatus as recited in claim 13, in which said valve element contains a vertical bleed passage with a second valve seat at its lower end, said valve means including a pilot valve element at the underside of said first mentioned valve element and movable relative thereto into and out of contact with said second seat, there being an operator extending downwardly from said actuating member through said bleed passage and into an aligned vertical passage in said pilot valve element, said reversing means including an element mounted rotatably to said body beneath said pilot valve element, and a flexible element connected at opposite ends to lower portions of said operator and said pilot valve element and extending about said rotatable element to reverse direction of the flexible element, there being a spring within said body disposed about said pilot valve element and said operator and urging said pilot valve element upwardly. 